<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title style="text-align:center ; width:100%; color: #999999;" ></title>
	</head>
	<body>
	
	
	<script>
				
	var  nowtime=new Date().Format("yyyy-MM-dd");
	var  oldtime=getPreMonth(nowtime); 
	var  oldmonthtime=oldtime+" - "+nowtime;
	console.log(oldmonthtime);
	
	
	//js日期格式化********************************************************************************************************************************//
 	Date.prototype.Format = function(fmt) {
            var o = {
                "M+" : this.getMonth() + 1,
                "d+" : this.getDate(),
                "h+" : this.getHours(),
                "m+" : this.getMinutes(),
                "s+" : this.getSeconds(),
                "q+" : Math.floor((this.getMonth() + 3) / 3),
                "S" : this.getMilliseconds()
            };
            if (/(y+)/.test(fmt))
                fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));
            for (var k in o)
            if (new RegExp("(" + k + ")").test(fmt))
                fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
            return fmt;
      }  
		
		
//js获取上个月的日期********************************************************************************************************************************//		
		 function getPreMonth(date) {
            var arr = date.split('-');
            var year = arr[0]; //获取当前日期的年份
            var month = arr[1]; //获取当前日期的月份
            var day = arr[2]; //获取当前日期的日
            var days = new Date(year, month, 0);
            days = days.getDate(); //获取当前日期中月的天数
            var year2 = year;
            var month2 = parseInt(month) - 1;
            if (month2 == 0) {
                year2 = parseInt(year2) - 1;
                month2 = 12;
            }
            var day2 = day;
            var days2 = new Date(year2, month2, 0);
            days2 = days2.getDate();
            if (day2 > days2) {
                day2 = days2;
            }
            if (month2 < 10) {
                month2 = '0' + month2;
            }
            var t2 = year2 + '-' + month2 + '-' + day2;
            return t2;
       }	 
	</script>
	
	</body>
</html>
